A back injury has forced Luciano Pavarotti to withdraw from eight concerts on his farewell tour, his spokeswoman announced.

The 70-year-old tenor will miss concerts in countries including Portugal, Brazil, Bosnia, and Chile while he undergoes physiotherapy for a "painful condition in his lower back" in New York.

He is scheduled to resume the tour on June 3 in Canada. An April 21 concert in Portugal has been rescheduled for September 29; dates for the other concerts, which will be re-scheduled after his treatment ends in May, are to be announced.

Back pain also led to his withdrawal from a March 18 appearance in Bel Horizonte, Brazil.

Pavarotti, who gave his final opera performance at the Metropolitan Opera in 2004, is in the midst of a worldwide concert tour. The tour was originally scheduled to end by his 70th birthday last October, but he has since said that he expects it to continue for another year or two before ending in Milan, London, Vienna, or the Met.